Method and apparatus for producing core yarn



Sept. 26, 1967- I A. G. M KINNON METHOD AND .AFPARATUS'FOR PRODUCING QORE YARN Filed Sept. 5, 1965 INVENTOR United States Patent 3,343,356 METHOD AND APPARATUS FOR PRODUCING CORE YARN Allen G. McKinnon, Asheboro, N.C., assignor to Burlington Industries, Inc., Greensboro, N.C., a corporation of Delaware Filed Sept. 3, 1965, Ser. No. 484,843

18 Claims. (Cl. 57-12) ABSTRACT OF THE DISCLOSURE A method and apparatus for producing a core yarn which includes compensating for the Variables of a continuous filament elastomer by pretensioning the filament and then applying additional tension to the filament as the filament is led to the front rolls of a spinning frame where it is collected and spun at uniform power with at least one roving to produce a core spun yarn.

The present invention relates to the preparation or spinning of a core yarn comprising a continuous filament elastomer used as the core and covered with fibers of a roving. More particularly, the present invention relates to a method of making the core yarn wherein a predetermined tension is applied to the core during spinning and to an apparatus for making such a yarn.

Heretofore, core yarns have been made with a con tinuous filament elastomer used for the core and with rovings used for a sheath about the core. In the prior apparatus and methods for making core yarns, the core yarn was either spun with the core filament in a completely relaxed condition or with the core filament placed under some tension. When the latter method was used, the continuous filament elastomer was stretched by driving the filament off of the supply package at a slower rate of speed than the filament was taken up on the front rolls of the spinning frame or spindle of the takeup package. This method proved quite satisfactory for cores in which the elastomer was rubber and there were not too many variables but, it was totally unsatisfactory for cores wherein the elastomer was spandex or the like which is subject to inherent and mechanical variables. In situations where rubber was used as a filament for .core yarn, there were not too many inherent and mechani- .spinning of the core yarn.

With the advent of spandex or the like for use as a filament or filaments in core yarns, many different variables had to be accounted for in order to satisfactorily produce a core yarn. Since spandex actually has no cure there is a far greater variation in its elongation to its breaking point. In other words, it has been found that there can be as much as t60*% in the variation in elongation in any one particular spandex and consequently this results in a wide variation in power of the spandex at any different elongation. Other considerations providing power variations in spandex which are not inherent to the same are the mechanical variables introduced by the apparatus in the processing of the spandex filament into the core yarn. For example, there are variations in adhesion of the spin finish on spandex filaments as various manufacturers use anywhere from no finish up to 15% finish. Still other variations are introduced into the processing of core yarn with a spandex filament, such as variations due to friction differences of the spandex with 3,343,356 Patented Sept. 26, 1967 various elements in which it comes into contact with in the apparatus, such as guide eyes, rolls, or the like.

Therefore, an important object of the present invention is to provide an improved method and apparatus for producing a core yarn having an elastomer subject to inherent and mechanical variables, such as spandex or the like, the method and apparatus compensating for the various inherent and mechanical variables of the elastomer in such a manner that the tension of the elastomer is maintained substantially constant as the elastomer is fed to the front rolls of the spinning frame.

Ancillary to the immediately preceding object, it is a further object of the present invention to provide an improved method and apparatus in which compensation for variables of the filament elastomer is immediate with no lag despite where the variable may occur, thereby resulting in production of a core yarn having uniform power throughout.

Another object of the present invention is to provide an improved method and apparatus for producing a core yarn utilizing as its core a filament of an elastomer such as spandex, the core being placed under tension or stretched to a point just below its breaking point so that the resulting product has uniform power. By such a method, a core yarn made of the same count will be uniform in tension at the point of use on a loom or a knitting machine and since the yarn would be used at virtually its end point of stretch, it would result in fabrics being woven or knitted therefrom free of such defects as power bands in woven fabrics and power bands and misplating in knitted fabrics.

A still further and important object and advantage of the present invention is that the method and apparatus contemplates producing the core yarn with the core at maximum stretch so that a maximum amount of core yarn can be made from each pound of elastomer used with all of the core yarn being made at the same uniform power. It has been found that factory run efficiencies for core yarns made according to the present invention at maximum stretch for a spandex filament is in the order of 86 to 94% and is substantially as good as laboratory runs.

A further object of the present invention is to provide a method and apparatus in which all core yarn, having a continuous filament elastomer of a particular spandex or the like, being produced on one or more spinning frames has the same or uniform power characteristics as the method and apparatus provides for immediate compensation when a variable, such as elongation and friction, is encountered in the continuous filament, thus maintaining the tension of the filament at the front rolls substantially constant during spinning.

These and other objects and advantages of the present invention will appear more fully in the following specification, claims and drawings in which:

FIGURE 1 is a schematic view of one type of improved apparatus for use with the present invention in producing a core yarn from at least one roving and a spandex continuous filament elastomer;

FIGURE 2 is a schematic plan view of the filament pretensioning device of FIGURE 1;

FIGURE 3 is a fragmentary side elevational view of a modified form of compensating weight means incorporating a revolving pulley rather than a hook element; and

FIGURE 4 is an end elevational view of the compensating weight means of FIGURE 3.

The present process or method may be described as one comprising the following steps: introducing an elastomeric filament, such as spandex, from a package to a spinning or drafting frame at the front rolls of the same while first subjecting the filament to a predetermined pretensioning or stretching of the same and then further subjecting the filament to a predetermined amount of tension which also compensates for variables which are inherent in the filament or which are a result of mechanical operating factors. The tensioned elastomeric filament is fed to the front rolls of the spinning or drafting frame under a substantially constant predetermined tension or power and is there collected with at least one roving or sliver which has been drafted, the roving or sliver being spun about the continuous filament with resulting core yarn having a twist of a desired amount. The critical feature of the process of the present invention is the applying of the predetermined amount of tension in such a manner that it also provides immediate compensation for variations of characteristics of the elastomeric filament so that when the spandex is delivered to the front rolls, it has the same power at all times thereby resulting in a uniform core yarn. It will be recognized that the amount of pretensioning of the continuous elastomeric filament and the amount of compensating load applied to the pretensioned elastomeric filament will vary depending upon operating factors such as the type and denier of the elastomeric yarn, the surface finishing of the elastomeric yarn, as well as the nature of the sheath fibers of the roving.

The term filament as used throughout the specification is intended to be either a mono-filament or a multifilament elastomer such as spandex material or the like. A polyurethane elastomer is especially desirable for use herein. One example of a suitable polyurethane elastomer is disclosed in U.S. Patent No. 2,953,839. Others are described in US. Patents 2,813,775, 2,813,776, 2,957,852 and British Patent 779,054. The amount of the core filament may be widely varied depending upon the end use contemplated.

The sliver or roving used herein to provide the sheath around the core filament may comprise textile fibers available in staple form. Thus, the fibers may include natural fibers such as cotton and wool, and synthetic or man-made fibers, such as rayon, nylon, polyacrylonitrile, polyethylene terephthalate, and the like. Of course, the roving or slivers may be made up of blends of two or more of these fibers if so desired and depending upon the final or end use contemplated.

Referring now to the drawings wherein like characters or reference numerals represent like or similar parts, FIG- URE 1 illustrates a supply package or bobbin of spandex or the like in mono-filament or multi-filament form, the package 10 being supported on a creel 12 in an upright manner so that the filament 14 is removed from the package vertically upwardly over the end of the same rather than unrolling the spandex filament 14 from the package. Mounted above the creel 12 and package 10 is a suitable pretensioning device or unit generally indicated by the numeral 16, the pretensioning device being suitably mounted on a support member or frame 18. One such pretensioning device may be of the type including a four-post tension member having vertically extending posts 20, 22, 24 and 26 thereon arranged on a large arc lying in a horizontal plane. Each post is provided with a pair of tension discs 28 and 30 between which the spandex filament 14 is passed about the outside of the arc of the post. Weights W of a selected predetermined amount are arranged to be received on the posts 20, 22, 24 and 26 in order to apply the desired amount of tension to the spandex filament 14. The weights W may be in the form of washers which slip over the posts and bear on the upper discs 30.

A guide element 32 is supported on the support member 18 at the inlet side of the tension device 16 and is arranged to receive the spandex filament 14 from the package 10 therebelow and change its direction to a horizontal direction as the filament passes into the pretensioning device 16. The guide element 32 may be a ceramic roller as shown in the drawing or it may be a ceramic pigtail type of guide. At the outlet side of the pretensloning device or unit 16 and also supported on the support member 18 is an outlet guide 34 which is either a roller or ball bearing pulley. Guide member 34 as well as guide member 32 is preferably ceramic of the conductive type so that any accumulation of a static charge on the spandex filament 14 will not build up but will be grounded out through the support member 18 for the tensioning device 16.

A second guide member 36, which is a pulley 38 suitably mounted on ball bearings carried by hearing blocks 40 is positioned in horizontal spaced relationship to the guide member 34. In more detail, the pulley 38 is positioned at the same vertical elevation as the guide member 34 and is horizontally spaced therefrom as well as being spaced vertically above the front rolls of a spinning frame schematically illustrated at 42. The continuous filament spandex 14 passes from the pretensioning device 16 over the suspension point defined by the guide member 34 as well as over the second suspension point defined by the guide member 36 and then is directed downwardly through a suitable guide eye 44 to the front rolls 46 of the spinning frame 42.

A suitable bobbin or package 48 mounted on a creel 50 provides a supply for a roving strand 52 of staple fibers. If desired a second package or bobbin 54 mounted on the creel 50 provides a second roving strand 56 of staple fibers. As shown in FIGURE 1 of the drawings, the roving strands 52 and 56 are fed through the guide eyes 58 and 60, respectively, to the guide eye 62 and from there between the back rolls 64 of the spinning frame 42. The roving strands 52 and 56 are further drafted in the drafting zone of the spinning frame generally designated at 66 and then are collected at the front rolls 46 along with the previously discussed continuous filament 14. As the staple fibers of the rovings 52 and 56 are spun about the filament 14 to produce a core yarn Y, they are then fed as the core yarn Y to the traveller 68 where the core yarn is wound onto a bobbin or take-up package B.

In order to provide a constant tension on the spandex filament 14 as it enters between the front rolls 46 of the spinning frame 42, and in order to compensate for inherent or mechanical variables encountered in the use of a particular spandex as the continuous fialment of the same is fed, the present invention provides for immediate compensation of these variables with no time lag at the point where they occur. As shown in FIGURE 1, a weight means 69 is freely suspended from the filament 14 between its support points as defined by guide members 34 and 36. The weight means 69 includes a hook element 70, which may be an Alsimag (conductive type quiller hook) and manufactured under No. 17147 by the American Lava Corp. and a lead weight 76. The hook element 70 which is provided with an elongated slot 72 having an opening 74 for entry of the filament 14 has a lead weight 76 suspended from the lower end thereof by wire 78 extending through the hole 80. The lead weight 76 is of a predetermined amount depending upon the amount of pretension applied to the filament 14 by the pretensioning device 16, the denier of the filament 14 and other operating variables. In more detail, the lead weight 76 and the hook 70 apply a predetermined load on the spandex filament 14 by gravity between the suspension points defined by the guide member 34 and 36. As the filament 14 is fed off of the package 10 through the pretensioning device 16 to the front rolls 46 of the spinning frame 42, the filament 14 will slide through the hook 70 so that the hook 70 and the weight will move relative to the filament 14. As mentioned at the outset of the specification, spandex has actually no cure and, therefore, it has greater varia tion in elongation to break and modulus than is found in rubber yarns. This elongation variation may be of elongation in any one particular spandex and assuming that a section of the strand of continuous filament 14 elongates more than another section the hook with its lead weight 76 will move downwardly and forwardly to compensate for this elongation so that there is no change in the power of the filarr'fent "at the front rolls 46 of the spinning frame 42. Conversely, if the elongation for a particular section is less, the reverse occurs in that the hook and weight will move upwardly so as to compensate for the lack of elongation in a particular section of the filament 14. If the spandex filament 14 lacks a predetermined mechanical drag at any point along the same, when that point causes an effect, for example, at the pretensioning device 16, the weight 76 and the hook 70 will take care of a lack of friction by descending so that a predetermined tension or power is maintained on the filament 14 at the point where the filament enters between the front rolls 46 and is collected with strands of roving 52 and 56. By applying the load to the spandex filament 14 between the spaced points of suspension and making this load freely supported on the spandex filament and dependent solely on gravity, there is no time lag in compensating for the variables encountered in the use of spandex filaments. Consequently, the core yarn Y spun by the spinning frame 42 is spun in such a manner that there is a constant and uniform power or tension on the core filament 14 at all times and, thus, the spun core yarn Y, when used on a loom or a knitting machine, provides for the weaving or knitting of fabrics which are free from such defects as power bands and misplating. In other words, the core yarns would be uniform in tension at their point of use and thus could be used at virtually the end point of their stretch thereby providing for a more uniform resulting fabric product.

Referring to FIGURES 3 and 4, it will be noted that in place of the hook element 70, a pulley wheel element 92 could be used to support or suspend the weight 76 from the spandex filament 14. In this modification, the spandex filament 14 is passed beneath the pulley wheel 84, the pulley wheel being provided with a bracket 86 for suspending the weight 76 therefrom.

Earlier in the specification, it was mentioned that the amount of pretension applied by the pretensioning device 16 as well as the load applied to the spandex filament 14 by the weight 76 would vary depending upon certain variable operating factors. It will be noted by reference to FIGURE 1 that the pretensioning device 16 is so arranged to progressively increase the tension placed on the spandex filament 14 passing therethrough. Stated another way, the pretensioning device 16 takes out a progressively increasing amount of stretch of the spandex filament 14. This is accomplished by providing an increasing amount-of load on the tension discs 30 by the weights W. This can be done by putting one weight washer W on post 20, two on post 22, three on post 24 and four on post 26. The weight means 69 then applies the final load to the spandex filament 14 and this load is usually just below the breaking point of the spandex.

In processing a core yarn having a spandex filament of 140 denier, it has been found that a pretension of a suitable amount can be applied to the spandex filament by applying washer weights W in progressively increasing amounts to the posts of the tensioning device 16, the washer weights having a total weight of approximately 3 /2 ounces. For this denier filament it has been found that the spacing of the support points defined by the guide members 34 and 36 is best when separated between 16 and 18 inches, the support points lying in the same horizontal plane. With the arrangement just described, the hook element 70 and weight 76, having a combined Weight of 80 grams, applies tension to the spandex filament 14 at the front rolls which is just below the amount of tension necessary to cause breaking of the filament. The above specific example is merely for illustrative purposes, it being understood that the weights will vary for different deniers as well as different variations in a particular spandex filament.

The improved process and the improved apparatus of the present invention which have heretofore been described and illustrated in the drawings, fully and effec- 6 tively accomplish the foregoing objects and advantages. However, it will be appreciated by those skilled in the art that certain modifications can be made to the process or apparatus described without departing from the spirit and scope of this invention.

Therefore, the terminology used throughout the specification and claims is for the purpose of description and not limitation with the scope of the invention being defined in the claims.

What is claimed is:

1. A method of producing a core yarn on a spinning frame or the like from a continuous filament elastomer and at least one roving comprising the steps of: drafting the roving in the drafting zone of the spinning frame; pretensioning the continuous filament elastomer as it is being. fed from a supply package; feeding the pretensioned elastomer over spaced points of suspension and then downwardly to the front rolls of the spinning frame; applying a predetermined load to the pretensioned elastomer intermediate the spaced points of suspension so as to apply a predetermined amount of tension to the elastomer as it is fed to the front rolls of the spinning frame; collecting the tensioned elastomer and the drafted roving at the front rolls of the spinning frame and then spinning the core yarn therefrom.

2. A method of producing a core yarn on a spinning frame or the like from a continuous filament elastomer and at least one roving comprising the steps of: drafting the roving in the drafting zone of the spinning frame; progressively increasing tension on the continuous filament elastomer as it is being fed from a supply package to provide a predetermined amount of .pretension on the elastomer; feeding the pretensioned elastomer over spaced points of suspension and then downwardly to the front rolls of the spinning frame; applying a predetermined load to the pretensioned elastomer intermediate the spaced points of suspension of the same so as to provide a predetermined amount of tension on the elastomer as it is fed to the front rolls of the spinning frame; collecting the tensioned elastomer and the drafted roving at the front rolls of the spinning frame and then spinning the core yarn therefrom.

3. A method of producing a core yarn on a spinning frame or the like from a continuous filament elastomer and at least one roving comprising the steps of: drafting the roving in the drafting zone of the spinning frame; applying a pretension to the continuous filament elastomer as it is being fed from a supply package; feeding the elastomer after pretensioning over spaced points ofsuspension and then downwardly to the front rolls of the spinning frame; freely suspending a predetermined weight from the elastomer intermediate the spaced points of suspension of the same so as to provide a predetermined amount of tension on the elastomer as it is fed to the front rolls of the spinning frame and so as to compensate for variations, such as elongation, modulus and the like, of the elastomer; collecting the tensioned elastomer and the drafted roving at the front rolls of the spinning frame and then spinning the core yarn from the same while the elastomer is under tension.

4. The method as claimed in claim 3 in which tension applied as the elastomer is fed from the supply package is progressively increased;

5. The method as claimed in claim 3 in which the tension of the elastomer as it is fed into the front rolls of the spinning frame is constant and of a magnitude to elongate the elastomer to a point just below its breaking point.

' 6. The method as claimed in claim 3 in which the spaced points of suspension over which the elastomer is fed lie in the same horizontal plane.

7. A method of producing a core yarn on a spinning frame or the like from a continuous filament elastomer and at least one roving comprising the steps of: drafting the roving in a drafting zone of the spinning frame; progressively increasing tension on the continuous filament elastomer as it is being fed from a supply package; then feeding the elastomer over spaced points of suspension lying in the same horizontal plane and then downwardly to the front rolls of the spinning frame; freely suspending a predetermined weight from the elastomer intermediate the spaced points of suspension of the same so as to provide a uniform tension on the elastomer of a magnitude to elongate the same to a point just below its breaking point, the freely suspended predetermined weight moving upwardly and downwardly depending upon variations of the elastomer so as to compensate for the same; collecting the tensioned elastomer and the drafted roving at the front rolls of the spinning frame and then Spinning the core yarn from the same while the elastomer is maintained under a uniform tension.

8. A method of feeding a continuous filament elastomer to the front rolls of a spinning frame at a uniform tension while the same is spun with roving into a core yarn comprising the steps of: feeding the continuous filament elastomer from a supply package and progressively increasing the tension as it is being fed therefrom so as to progressively stretch the same; then feeding the elastomer over spaced points of suspension while applying a predetermined load under the influence of gravity to the elastomer intermediate the spaced points of suspension so as to provide a substantially uniform tension in the elastomer; and then feeding the elastomer to the front rolls of the spinning frame.

9. The method as claimed in claim 8 in which the feeding of the elastomer from the supply package is generally upwardly over the end of the supply package and the progressively increasing tension is applied to the elastomer while the elastomer is being fed in a generally horizontal direction.

10. The method as claimed in claim 8 in which the continuous filament elastomer is spandex.

11. Apparatus for producing a core yarn from a continuous filament elastomer and at least one roving comprising: a spinning frame having a drafting zone and front rolls; means for feeding roving to and through the drafting zone and front rolls; and means for feeding the continuous filament elastomer at a substantially constant tension to the front rolls, said last mentioned means including a first means for applying a pretension to the elastomer and a second means for applying additional tension to the elastomer after the same has been pretensioned, said second means also compensating for variations, such as elongation, modulus and the like, in the elastomer and including a Weight freely suspended from and movable relative to the elastomer intermediate its feed to the front rolls and the first means for applying a pretension to the same.

12. Apparatus as claimed in claim 11 in which said first means for applying a pretension to the elastomer includes means for progressively stretching the elastomer as the same is received from a supply package.

13. Apparatus for producing a core yarn from a continuous filament elastomer and at least one roving comprising: a spinning frame having a drafting zone and front rolls, means for feeding roving to and through the drafting zone and front rolls, a supply package for the continuous filament elastomer; pretensioning means for receiving the elastomer from the supply package and applying a pretension to the same; spaced suspension means positioned above the spinning frame for receiving the elastomer fed from the pretensioning means and supplying the same to the front rolls of the spinning frame; and weight means freely suspended from and movable relative to the elastomer intermediate the spaced suspension means.

14. Apparatus as claimed in claim 13 in which said Weight means includes a hook element having a weight carried therefrom, said hook element being freely slidable relative said elastomer.

15. Apparatus as claimed in claim 13 in which said weight means includes a pulley wheel having a Weight supported therefrom, said pulley wheel being arranged to ride on the elastomer.

16. Apparatus as claimed in claim 13 in which said pretensioning means includes a four-post tension member, each post of said tension member having weighted tension discs thereon bearing on the elastomer, the weighted tension discs progressively increaing in Weight in the direction of feed of elastomer through said tension member.

17. A core yarn product produced by the process of claim 1.

18. A core yarn product produced by the process of claim 7.

References Cited UNITED STATES PATENTS 2,860,844 11/1958 Price 242 3,017,740 1/1962 Humphreys 57-163 FOREIGN PATENTS 858,002 12/1952 Germany. 774,908 5/1957 Great Britain.

FRANK J. COHEN, Primary Examiner.

WILLIAM S. BURDEN, Assistant Examiner. 

11. APPARATUS FOR PRODUCING A CORE YARN FROM A CONTINUOUS FILAMENT ELASTOMER AND AT LEAST ONE ROVING COMPRISING: A SPINNING FRAME HAVING A DRAFTING ZONE AND FRONT ROLLS; MEANS FOR FEEDING ROVING TO AND THROUGH THE DRAFTING ZONE AND FRONT ROLLS; AND MEANS FOR FEEDING THE CONTINUOUS FILAMENT ELASTOMER AT A SUBSTANTIALLY CONSTANT TENSION TO THE FRONT ROLLS, SAID LAST MENTIONED MEANS INCLUDING A FIRST MEANS FOR APPLYING A PRETENSION TO THE ELASTOMER AND A SECOND MEANS FOR APPLYING ADDITIONAL TENSION TO THE ELASTOMER AFTER THE SAME HAS BEEN PRETENSIONED, SAID SECOND MEANS ALSO COMPENSATING FOR VARIATIONS, SUCH AS ELONGATION, MODULUS AND THE LIKE, IN THE ELASTOMER 